Typically, blood withdrawal from the body, for donations or test purposes, is performed with a syringes by inserting a needle into the median cubital vein between the biceps and the forearm muscles of the arm. This technique, of course, is a relatively simple procedure which usually employs a vacuum tube insert to store the blood and which facilitates withdrawal of blood through the suction created by the vacuum tube. Without the assistance of a vacuum, blood pressure alone is generally insufficient to extract large quantities of blood in a short time span. This procedure, however, often cannot be performed on infants, smaller children, elderly individuals, or the extremely ill because their physical stature prevent withdrawal of large quantities of blood. Moreover, many blood testing procedures do not require large volume blood specimens.
Consequently, blood lancets were developed as a means for extracting capillary blood which is most commonly withdrawn from the fingertips. Approximately 4 million of these procedures are performed yearly in the United States. These blood specimens facilitate screening tests and supply blood from those who can ill-afford furnishing large quantities.
Originally, blood lancets were merely plates having a surgical blade extending therefrom formed to pierce the fingertip using a jabbing motion. Typical of such devices is the Bard Parker surgical blade. These crude blades frighten children and adults alike.
More recently, the blood lancet has evolved into elongated plastic devices which include a piercing needle or blade protruding from one end thereof. Typically, the technician holds the patient's hand, with the palm facing upward, and jabs the fingertip with the needle in a motion similar to the Parker blade. When the finger starts to bleed, the technician places a vial or blood absorbing blotter adjacent the perforation and extracts the blood by squeezing the fingertip. When more than a few drops of blood are to be withdrawn, this procedure is performed until approximately 750 microliters of blood are collected in the vial, upon which the vial is closed, and subsequently, tested.
One problem associated with this technique is that the overall procedure is inaccurate and cumbersome. The patient must rely on the technician's accuracy in jabbing their finger. The medical technician, may miss the target area, which will require piercing the finger twice in order to withdraw the properly needed amount. Subsequently, the technician is required to separately hold the vial against the finger to gravitationally capture the blood secreted from the perforation while simultaneously pressurizing the finger. This combination is rather clumsy and may result in spillage of the specimen or dropped vials. Not only does this waste time and burden the patient, the specimen may potentially be contaminated as well.
Another problem associated with this procedure and the blood lancet itself is that it exposes the medical technician to contact with the donor's blood. The issue of accidental sticks and also of aerosolized blood has come to the forefront of concern first as a result of hepatitis caused by cross contamination and yet more recently by the advent of the very serious worldwide epidemic of acquired immune deficiency syndrome (AIDS). Many efforts are being made around the world to minimize the possibility of health care workers being accidentally contaminated by sticks from sharp instruments such as cutting implements, hypodermic needles and finger lancets. For instance, it is now common procedure for the medical technician to wear protective gloves whenever handling blood or instruments coming in contact with blood.
While these gloves provide greater protection to the technician, contact with the patient's blood is common. Moreover, the exposed lancet still poses an unsafe and unsanitary threat. Accidental sticks by the lancet easily pierce the glove and skin so that the medical technician must practice an abundance of caution when handling these devices.
This problem has been overcome by providing a spring mechanism which cooperates with the lancet to withdraw it into a receptacle after puncture of an appendage. Hence, exposure to an unsafe and unsanitary lancet is minimized. Subsequent to puncture and withdrawal of the lancet, however, the technician is still required to separately hold a vial against the finger to gravitationally capture the blood secreted from the perforation while simultaneously pressurizing the finger. Contact with the blood flowing from the perforation is still poses an immediate hazard. Typical of such spring-loaded lancets are disclosed in U.S. Pat. No. 4,616,649 to Burns; and U.S. Pat. No. 5,026,388 to Ingalz.
Accordingly, it is an object of the present invention to produce a self-contained blood withdrawal apparatus and method which promotes safety of use.
It is another object of the present invention to provide a self-contained blood withdrawal apparatus and method which reduces patient pain, apprehension and trauma.
Still another object of the present invention is to provide a self-contained blood withdrawal apparatus and method which punctures the skin on the first attempt and more accurately pierces the designated area.
Yet another object of the present invention is to provide a self-contained blood withdrawal apparatus and method which facilitates removal and storage of the specimen.
It is a further object of the present invention to provide a self-contained self-contained blood withdrawal apparatus and method which is durable, compact, easy to maintain, has a minimum number of components, is easy to use by unskilled personnel, and is economical to manufacture.